1) The “Administration Email” is only used for administration purposes, like sending the site admin notification emails. It has no effect on the front end of your site.
2) The “Display Name publicly as” field displays the name on the page itself (front-end). It has no effect on the author URL.
3) WordPress ALWAYS uses the sanitized version of the user’s username for the author URL. Changing the public display name has no effect on this, as mentioned above.
Your “problem” is occurring because you used the email address as the username. This is permitted by not recommended (one reason being the very problem you’re reporting).
You can:
— Create a new user with the desired username (not an email address) and delete the current one
— Or use a plugin to change the username of the current user from the email address to something else: https://projectdmc.org/plugins/change-username/
Good luck!
Wow…… that was easy!! Thank you very much for the help, problem solved 🙂